New method of fault location on double-circuit two-terminal transmission lines

A new method to locate faults on double-circuit transmission lines is described in this paper. This method only uses the fundamental components (50/60 Hz) of fault and prefault currents, measured at one of the ends of the line. From these measured values a function is established from which the point at which a fault occurred is determined. The definition of a new concept called the ‘distance factor’ will allow a method to be developed which is independent of fault resistance, type of fault, mutual coupling between the two circuits and initial prefault conditions. The accuracy of this method has been assessed by using a fault simulation software program. In the first stage the accuracy of the method was determined on the basis of accurate input data. In the second stage the sensitivity of the method was analyzed from errors in the input data.